Thinking on it some more, most of what's wrong with healers ultimately comes back to the oGCDs. Healers have gotten more of them with each expansion, yet fights have not increased their damage output (relative to player HP) to compensate. As a result, healing has gotten easier and easier with each expansion.

Using WHM as an example, back in ARR, it had one oGCD direct heal: Benediction. Its other oGCDs were Divine Seal, which was a precursor to Largesse, and Presence of Mind. Both of which interacted with GCD heals to make them better. Shroud of Saints was a proto-Lucid for MP recovery. And that's it. That's the sum total of WHM's 2.0 oGCD toolkit.

Now, in 5.0, WHM has the following direct heals in its oGCD toolkit:

- Benediction
- Asylum
- Assize
- Tetragrammaton
- Divine Benison

That's five oGCD tools ready and available to deal with scripted tankbusters and raidwides. That's not even counting further healing-boosting oGCDs like Temperance or Plenary Indulgence or Largesse.

If you stop and think about it, actually, almost all of the new healing abilities added since 2.0 have been oGCDs. The Afflatus spells are on the GCD, but that's it. SCH and AST didn't get any new healing GCDs to play with. It shouldn't have been hard to add a couple extra healing GCD spells that interact with the existing kit in some way, yet it never happened.